AT&T

If you want to follow conversation threads relating to this show on social media—whether Twitter, Facebook, or Instagram, Tumblr—you know to look for the hashtag: #99pi. In our current digital age, the hashtag identifies movements, events, happenings, brands—topics of all kinds. The “#” didn’t always have this meaning, though. It’s had a few different lives.

San Francisco Sheriff Ross Mirkarimi has been sentenced to a day in jail and three years probation for falsely imprisoning his wife. He will receive credit for time already spent in jail. The sheriff will also attend a year of domestic-violence intervention classes and perform 100 hours of community service...